IFR aircraft departed airport and conflicted with an opposite direction IFR arrival.

Attributes
ACN	109839
Time
Date	198904
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : stp
State Reference	MN
Altitude	agl bound lower : 0 agl bound upper : 200
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : msp tower : stp artcc : zla
Operator	general aviation : personal
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Flight Phase	cruise other
Route In Use	arrival other
Flight Plan	IFR
Aircraft 2
Operator	general aviation : corporate
Make Model Name	Light Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : takeoff
Route In Use	departure other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Experience	controller military : 4 controller radar : 8 flight time last 90 days : 5 flight time total : 600
ASRS Report	109839
Person 2
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact
Consequence	Other
Miss Distance	horizontal : 12000 vertical : 500
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error Inter Facility Coordination Failure

Narrative:

I was watching a trnee on the north satellite position and working an small transport X to stp. Stp requested a release on an light transport Y, opp direction. The small transport X was still about 12 NM out at this time, so we issued a departure release void in 1 min. At about the void time, stp called up with information concerning another arrival being circled because light transport Y was on the runway. At this point I perceived that stp had cancelled the release clearance because that is what I was just going to do. Also at this point, had I heard what stp had said, I still had enough time to use an alternate plan. I still had small transport X on frequency. In fact, I instructed my trnee to send small transport X over to stp tower because I believed that the situation had been taken care of. With the interaction taking place with my trnee, trying to instruct, and my error in judgement, this became a serious error. I have been an fpl controller for over 5.5 yrs, an air force controller for 4 yrs, a commercial pilot with instrument rating, and have always done a good job. I believed that I had enough going for me to make this determination of the release, and also believed that I had taken care of my error with stp. In fact, I heard what I wanted to rather than what was actually said. I rest my case.

Original NASA ASRS Text

Title: IFR ACFT DEPARTED ARPT AND CONFLICTED WITH AN OPPOSITE DIRECTION IFR ARR.

Narrative: I WAS WATCHING A TRNEE ON THE N SATELLITE POS AND WORKING AN SMT X TO STP. STP REQUESTED A RELEASE ON AN LTT Y, OPP DIRECTION. THE SMT X WAS STILL ABOUT 12 NM OUT AT THIS TIME, SO WE ISSUED A DEP RELEASE VOID IN 1 MIN. AT ABOUT THE VOID TIME, STP CALLED UP WITH INFO CONCERNING ANOTHER ARR BEING CIRCLED BECAUSE LTT Y WAS ON THE RWY. AT THIS POINT I PERCEIVED THAT STP HAD CANCELLED THE RELEASE CLRNC BECAUSE THAT IS WHAT I WAS JUST GOING TO DO. ALSO AT THIS POINT, HAD I HEARD WHAT STP HAD SAID, I STILL HAD ENOUGH TIME TO USE AN ALTERNATE PLAN. I STILL HAD SMT X ON FREQ. IN FACT, I INSTRUCTED MY TRNEE TO SEND SMT X OVER TO STP TWR BECAUSE I BELIEVED THAT THE SITUATION HAD BEEN TAKEN CARE OF. WITH THE INTERACTION TAKING PLACE WITH MY TRNEE, TRYING TO INSTRUCT, AND MY ERROR IN JUDGEMENT, THIS BECAME A SERIOUS ERROR. I HAVE BEEN AN FPL CTLR FOR OVER 5.5 YRS, AN AIR FORCE CTLR FOR 4 YRS, A COMMERCIAL PLT WITH INSTRUMENT RATING, AND HAVE ALWAYS DONE A GOOD JOB. I BELIEVED THAT I HAD ENOUGH GOING FOR ME TO MAKE THIS DETERMINATION OF THE RELEASE, AND ALSO BELIEVED THAT I HAD TAKEN CARE OF MY ERROR WITH STP. IN FACT, I HEARD WHAT I WANTED TO RATHER THAN WHAT WAS ACTUALLY SAID. I REST MY CASE.

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.